Many naturally occurring and synthetic ergolines are known to bind in to neurotransmitter receptors, such as, for example, dopamine, noradrenaline and serotonin receptors and to function as unselective agonists or antagonists at these receptors. Compounds that are selective or specific for certain specific receptors may lead to desirable therapeutic actions while eliminating or reducing unwanted side effects. For example, selective serotonin antagonists have been developed for the treatment of migraine and more recently, selective dopamine agonists for the treatment of Parkinson's disease and hyperprolactinemia have been discovered.
However, there is a continuing need for less toxic ergoline derivatives to treat a variety of disorders such as, for example, migraines wherein selective agonism (e.g., 5-HT1D and 5-HT1) and antagonism (e.g., 5-HT2B) on multiple neurotransmitters receptors achieved by a single compound is desirable.